title: Effects of dilation on electronic-ETDRS visual acuity in diabetic patients.
abstract: OBJECTIVE
  To evaluate the effect of pupillary dilation on electronic-ETDRS visual acuity (EVA) in diabetic subjects and to assess postdilation EVA as a surrogate for predilation VA.
  
  
  METHODS
  DRCR.net-protocol refraction and EVA were measured before and after dilation in diabetic subjects by independent, masked examiners.
  
  
  RESULTS
  In 129 eyes of 66 subjects, the median (25th, 75th percentiles) predilation EVA score was 69 (54, 86) (Snellen-equivalent 20/40(-1) [20/80(-1), 20/20(+1)]). Predilation VA was >or=20/20, <20/20 to 20/40, <20/40 to 20/80, and <20/80 in 29%, 19%, 26%, and 26% of eyes, respectively. Median EVA change postdilation was -3 letters (-7, 0). The absolute change in EVA score was >or=15 letters (>or=3 ETDRS lines) in 9% of eyes and >or=10 letters (>or=2 ETDRS lines) in 19% of eyes. Extent of change (range +12 to -25 letters) was associated with baseline VA. No relationship was identified between EVA change and gender, race, lens status, refractive error, DR severity, or primary cause of vision loss.
  
  
  CONCLUSIONS
  In an optimized clinical trial setting, there is a decline in best corrected EVA after dilation in diabetic subjects. The large range and magnitude of VA change preclude using postdilation EVA as a surrogate for undilated VA.
authors.affiliation: Beetham Eye Institute and Eye Research Section, Joslin Diabetes Center, Boston, Massachusetts, USA. drcrx2@jaeb.org
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Sun
authors.forename: Lloyd Paul
authors.initials: LP
authors.lastname: Aiello
authors.forename: Margaret
authors.initials: M
authors.lastname: Stockman
authors.forename: Jerry D
authors.initials: JD
authors.lastname: Cavallerano
authors.forename: Ann
authors.initials: A
authors.lastname: Kopple
authors.forename: Sharon
authors.initials: S
authors.lastname: Eagan
authors.forename: Haijing
authors.initials: H
authors.lastname: Qin
authors.forename: Craig
authors.initials: C
authors.lastname: Kollman
authors.forename: Roy W
authors.initials: RW
authors.lastname: Beck
authors.forename: Adam R
authors.initials: AR
authors.lastname: Glassman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003920:Diabetes Mellitus / Q000503:physiopathology*; D003936:Diagnosis, Computer-Assisted; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000008:administration & dosage; D010656:Phenylephrine / Q000008:administration & dosage; D011680:Pupil / Q000187:drug effects / Q000502:physiology*; D015203:Reproducibility of Results; D014331:Tropicamide / Q000008:administration & dosage; D014787:Vision Tests / Q000295:instrumentation / Q000592:standards; D014792:Visual Acuity / Q000502:physiology*
chemical_list: D004338:Drug Combinations; D009184:Mydriatics; D010656:Phenylephrine; D014331:Tropicamide